dBAviktning

dBAviktning, often written as dB(A) or dBA, refers to a sound level measured with A-weighting. A-weighting is a standard frequency weighting used in acoustics to approximate the sensitivity of the human ear, so dBAviktning expresses perceived loudness rather than the raw sound pressure.

The A-weighting curve adjusts the spectrum by attenuating low frequencies and reducing very high frequencies, while emphasizing midrange frequencies where human hearing is most sensitive. Consequently, a sound that sounds loud to a person will tend to have a higher dBAviktning value than its unweighted level, especially for noises rich in midrange content.

Measurement and standards: Modern sound level meters apply the A-weighting filter in real time and report values such as L_Aeq, which is the time-averaged A-weighted level, or L_Amax for peak values. International and national standards for measurement and reporting include ISO 1996 and IEC 61672 (and their national adoptions), which define how the weighting is applied and how results should be presented.

Applications and limitations: dBAviktning is widely used in occupational health, environmental noise assessments, building acoustics, and consumer sound level meters. It is not a direct measure of loudness, and can misrepresent impulsive or very low-frequency sounds. For such cases, other weightings like C-weighting or Z-weighting may be used. The interpretation of dBAviktning also depends on calibration, microphone characteristics, and measurement duration.